What killed lidya the first time you played Skyrim? When I played it, I had to kill her, as she turned traitor and started attacking some imperial soldiers I was working with to get an ancient crown.
She never died, just disappears one day. I was exploring a cave and suddenly realized she wasn't there. I waited, fast traveled, checked my house, even reloaded two or three old saves and still couldn't find her. No clue what heppened to her, she was just gone. I'd made her some good armor too by that point, and she was carrying most of my good loot.
Horsey, never abandoned me though. Even after making him scale every damn mountain in that frozen waistband, he was always right there when I'd fast travel, ready to go. He was my only true friend in that game.
She died many times but I kept reloading the save. By dragons, mammoths, anything because she sucks at fighting. She's supposed to protect me, but I end up having to protect her. But she carries my stuff so I keep her alive.
She dropped to the ground during a fight with bandits to recover health like companions usually do when they are about to die... and right as I released the "shoot arrow" button aiming at an enemy, she popped up directly in front of me and managed to get shot right in the forehead by my arrow. Her body was then propelled into a river by the arrow, and proceeded to get thrown over a waterfall at the end of the river. I looked for her body for like 20 minutes to get the loot she was carrying back and never found it. It's as if she did it on purpose just to spite me.
I really don't get why so many people talk about Lydia like she's such an essential part of the game - there are fucking tons of followers you can get in Skyrim. Assuming you go straight to Riverwood at the beginning, you can take either Faendal or Sven as your first follower, and in Whiterun you can easily get Uthgerd or hire Janessa if you've worked up 500 gold, and this is all before killing your first dragon. Maybe its just me being too chicken to fight dragons when I first played the game, but I didn't even meet Lydia until long after I had used many other followers.
Well the last time she died before I reloaded she, for whatever reason, decided to attack a group of giants outside Whiterun. One giant down, I turn around and "SLAM". There she is flying into oblivion and never coming back down. This may be a glitch in the game, there have been times where I have been exploring and mammoths appear out of the sky just to fall to their deaths. Oh Lydia lol.
It's not that she is essential or useful in any way, like you said there are lots of followers available. It's just really funny and ironic that she is assigned to be your first housecarl/personal bodyguard by the Jarl, yet manages to die every possible way. Not much of a bodyguard when she can't even protect herself.
I've only ever lost followers by killing them myself. They never actually get killed by enemies, just beaten down and I have to watch where I shoot or swing my weapons in case I hit them and finish them off. My first ever housecarl was Iona in Rfiten and she was awesome. I expected her to die easily based on my previous experience with games that have AI partners. But she took down a forsworn briar heart that I was struggling with. The first time she died on me was when I got too trigger happy with a staff of fireballs.
I think the first time played skyrim I was little and I didn't really get the concept. So when I first got her she died at the hands falmer.